In order to prevent an operator from being damaged by spattering matters and various harmful rays caused by welding-arc ignition, the operator usually wears a welding helmet on his/her head during a welding operation. In a conventional welding helmet, a light filter is an important component for protecting the operator's eyes from the harmful rays. Usually, the operator should first observe the position where the welding-arc ignition will occur. Then, the operator wears the conventional welding helmet on his/her head to carry out a blind operation. This kind of blind operation may lead to much inconvenience on welding sites.
For this reason, an auto-darkening welding helmet has been developed in recent years. The auto-darkening welding helmet is generally equipped with an auto-darkening filter. The auto-darkening filter can work mainly because it is provided with a liquid crystal panel. The liquid crystal panel is transparent before the welding-arc ignition. The liquid crystal panel becomes opaque at the moment of the welding-arc ignition starting, so as to protect the operator's eyes. The auto-darkening welding helmet is usually provided with an adjustment knob or button. Therefore, before wearing the welding helmet, the operator has to hold it in hand to set operating parameters, such as SENSITIVITY, delay time, shade, and weld mode or the like, of the auto-darkening filter. After the setting, the operator can wear the welding helmet on his/her head to carry out the welding operation. In case that the operating parameters must be adjusted repeatedly on some welding sites (for example to alter the weld mode or SENSITIVITY), repeatedly taking off/wearing the helmet will extremely consume the operator's energy, which may negatively affect the quality of welding.
In the course of taking off the helmet, setting the parameters and wearing the helmet again, the operator's eyes have to make constant self-regulation to adapt to bright or dark environmental change. Individual operators may even feel discomfort such that their welding work may be affected. In severer cases their eyes may be permanently damaged.